A tool for working a workpiece has a slot provided between a pair of extremities at its distal end. The extremities have cutting blades mounted thereon. The slot is configured to receive a plate. The tool has a conduit running along its axis for communication of pressurized fluid to the slot and plate. The plate directs flow of the pressurized fluid outward toward the extremities. The resulting outward force causes the extremities to bend outward, thereby urging the cutting blades outward for cutting, reaming, or other working of the workpiece. The resilience of the tool causes the extremities to return back inward when the fluid pressure is reduced. A plate may be configured to receive a wafer for transferring force from the pressurized fluid to the extremities.